The combination of electrical stimulation and a nanotech surface composed of carbon nanotubes dispersed in polycarbonate urethane was found to attract cartilage-forming cells, which might lead to a treatment to regenerate lost or damaged cartilage. Excerpts from “Brown researchers work toward ending cartilage loss” (via KurzweilAI.net):

…Brown University nanotechnology specialist Thomas Webster has found a way to regenerate cartilage naturally by creating a synthetic surface that attracts cartilage-forming cells. These cells are then coaxed to multiply through electrical pulses. It’s the first study that has shown enhanced cartilage regeneration using this method; it appears in the current issue of the Journal of Biomedical Materials Research, Part A (abstract).

…Webster and his team, including Brown researcher Dongwoo Khang and Grace Park from Purdue University, found that the tubes, due to their unique surface properties, work well for stimulating cartilage-forming cells, known scientifically as chondrocytes. The nanotube’s surface is rough; viewed under a microscope, it looks like a bumpy landscape. Yet that uneven surface closely resembles the contours of natural tissue, so cartilage cells see it as a natural environment to colonize.

“We’re tricking the body, so to speak,” Webster said. “It all goes back to the fact that the nanotubes are mimicking the natural roughness of tissues in the first place.”

…The team plans to test the cartilage regeneration method procedure with animals, and if that is successful, to conduct the research on humans.

Webster’s cartilage regeneration studies parallel research he has done with bone regeneration and implants that was published last year in Nanotechnology. The principles are the same: Bone cells are more apt to adhere to a rough carbon nanotube surface than other surfaces and to colonize that surface. And tests by scientists in Japan and elsewhere have shown that electrical pulses stimulate bone cell growth.